… getting the wrong answer fast is not an improvement over the right answer slow

Category Archives: Raspberry pi

So, it happened again, the micro SD card in the Raspberry pi used to host this blog started to fail:

mmc0: Timeout waiting for hardware interrupt

… and my Raspberry pi2’s kill count now stands at 3 SD cards.

Recovery is not a problem since it’s backed up regularly, but it’s an irritating issue; whilst I don’t expect massive endurance from any of these cards, I expect them to last longer than they have as the system isn’t write heavy. The symptoms so far are never the same; card 1 simply became read-only, card 2 started exhibiting silent file corruption fixable by re-writing the data, and now the issue with card 3 manifests itself as the server randomly hanging whenever the system hits a particular portion of the card. Card 1 was class 6 and branded “Maxell”, card 2 was class 10/U1 and branded “Kingston” and card 3 a “Toshiba” class10/U1.

The underlying issue could be anything; firmware, power or pi2 design, but because the failures are always different I think this is purely down to card quality and wear out. Historically this server was hosted on a Cobalt Qube2 with an 8gb flash card, and then on a Raspberry pi model B with a 16GB SD card; both for long periods of time without issue. Both cards were also branded “SanDisk”; although I’ve no idea if that really makes any difference.

This time I’ve brought the site back up on the Raspberry pi model B, mainly because I’d not got a suitable working micro SD card for the pi2. We’ll see how it goes, but it might be time to move some things to tmpfs!

Today the server this site runs off got a well needed upgrade in the form of a Raspberry pi model 2B. I’m normally not one to rush out and buy the latest new gadget; my policy is if it aint broke don’t fix it. However wordpress had been taking it’s toll on the trusty old model B, and the timing of the 2B was perfect as I’d even started considering getting proper hosting again.

Raspberry pi model B2 and B side by side.

I’m still amazed at how fast technology gets smaller and cheaper these days. It seems like only yesterday I was marvelling at the qube2: